1. Field of the Invention
The present invention relates to projectiles, such as arrows, designed to penetrate a target to varying depths. It also relates to munitions containing a plurality of these projectiles designed, for example, to be placed on board vectors such as missiles, rockets etc.
2. Description of the Prior Art
The European patent application No. 88110917.7, filed on behalf of Diehl GMBH & Co. discloses a munition of this type, designed more especially to neutralize concrete taxiway circuits, runways or roads. It has an set of arrows contained in a package provided with a parachute and a propellant charge. After the munition is dropped from a carrier, first of all the parachute opens out. Then, once the verticality of the package is accurate, the propellant charge is set off. Then, once the entire propellant charge is consumed, a second charge is ignited to expel the arrows from the package, in order to give them a velocity in addition to that of the package.
The principle implemented in the above-mentioned invention is therefore, as in the other presently known systems, that of communicating a high velocity to the arrows towards the target to obtain efficient penetration which, if necessary, may be limited by radial projecting features in the rear part of the arrows.
However, the expulsion, by gun effect, of a bundle of projectiles at high relative velocity generally leads to high degrees of obliquity, that are not compensated for at short ranges and are highly detrimental to penetration. Furthermore, as the obliquity is highly variable since it also depends to a great extent on the wind, it is almost impossible to obtain a precise penetration depth or to make it uniform, notably because of the nutational motion of the projectiles, the direction of which is clearly a random direction at the instant of impact. In the neutralization of relatively soft targets, such as taxi-ways or roads, there is then a risk that a large part of the arrows will penetrate too deeply, without leaving any projecting parts.
Moreover, the principle of expelling a plurality of projectiles at high velocity from one and the same munition has another drawback arising out of the fact that these munitions are generally dropped at low altitude. This leads to a concentration (in a zone of a few decimeters) of the impacts of the arrows of one and the same munition, and hence to a distribution in "bouquets" of non-uniform density. This characteristic results in an appreciable loss in efficiency, especially when the targets aimed at are other than aerodrome runways, taxi-way circuits or roads.